NTC-13A: Checking Engine Mechanical Systems

NOTE: If coming to this test from a Heated Oxygen Sensor (HO2S) test, and rich or lean condition is not corrected after checking items listed below, replace Powertrain Control Module (PCM). Perform TEST VER-2A.

At this point in diagnostic test procedure, all engine control systems have been determined to be operating as designed and not causing a driveability problem. Following additional items should be checked as possible causes:
- Ensure engine vacuum is at least 13 in. Hg In Neutral:
- Check valve timing:
- Check engine compression:
- Check for exhaust system restrictions:
- Check PCV system for proper function:
- Ensure engine drive sprocket is properly positioned:
- Check torque converter stall speed (A/T):
- Check power brake booster for internal vacuum leak:
- Check for fuel contamination:
- Ensure injector control wire is connected to correct fuel injector and injector is not plugged or restricted:
- Check for pertinent Technical Service Bulletins (TSBs):
- If equipped with distributor, set distributor position. Go to next step.
  WARNING: Avoid contact with moving engine parts.
  
  NOTE: Setting distributor position does not adjust ignition timing. Ignition timing is controlled by PCM.
Connect scan tool to data link connector. Select SET SYNC from scan tool menu. Start engine and allow it to idle. Observe scan tool display. If scan tool does not display IN RANGE, loosen distributor hold-down clamp bolt and rotate distributor until reading is as close to zero degrees as possible, and IN RANGE message is displayed. Tighten hold-down clamp bolt to 16.7 ft. lbs. (22.5 N.m).